Trees pruned at this time of year has a stunting affect on growth. It sounds like that may be exactly what you want. Trees are more vulnerable to disease when pruning this late so be careful. Remove vertical growth and open the center so light and air can get through. May want to take precaustions against fungal and pest issues after pruning this time of year, as you will have many open wounds.

pruning this time of year is unsuggested, try to wait for next year it would be far better...

Posted by wal4444 none (My Page) on Wed, May 30, 12 at 13:34

pruning this time of year is unsuggested, try to wait for next year it would be far better...

Any time during the dormant season, next year?

Ringa,

Pruning peaches this time of year in GA is perfectly fine. You'll have rapid callus formation of wounds at this time.

There are a couple of considerations that may be relevant to your proposed pruning. First, if you remove 1/2 the tree it may remove so much foliage that scaffolds underneath could become sunburned. I've had this happen to scaffolds before when I drastically prune this time of summer. So you'll either want to leave some foliage to shade the scaffolds, or save your most drastic pruning for early spring.

Second, lesser peach tree borer is more prevalent in the Southeast. The moth preferentially attacks damaged tree tissue (like large pruning wounds) so you'll want to keep an eye on any large cuts you make regardless of what time of the year you prune.

Mapler,

You're in a much colder zone. Trees are generally more susceptible to winter kill when pruned late in the season or during winter. It's fine to prune now, but I wouldn't advise pruning later than July. Any major pruning is probably best done late dormant/early Spring for your zone.